A charged particle beam device for detecting charged particles obtained by irradiation of a sample with a charged particle beam such as an electron beam has a detector for detecting the charged particles. For example, in a case of detecting electrons emitted from a sample by scanning a sample, an electron beam of a positive voltage at about 10 kV is applied to an electron detector, thereby guiding the electrons to a scintillator of the charged particle detector. Light generated in the scintillator by collision of electrons is guided along a light guide, converted into electric signals by a photoreceiving element such as a photomultiplier tube to form image signals or waveform signals.
Patent Literature 1 describes a light guide attached to a scintillator. Further, Patent Literature 1 describes a configuration of providing a tilted surface to a light guide for guiding light emitted from the scintillator to a PMT (photomultiplier tube). Patent Literature 2 describes a light guide using a material of high transparency, for example, an acrylic resin. Further, the cited reference 2 shows a device of guiding light generated in a scintillator by way of a light guide and allow the light to enter a photoelectric conversion element including, for example, a photomultiplier tube or a semiconductor photoreceiving element. Further, it describes a scintillator structure in which a surface on the side opposite to the incident surface of the electrons is formed as a tilted surface in order to guide light at high efficiency to the light guide.